The present invention relates to an apparatus and method for accessing a data file via a data communication network.
In recent years, there has been explosive growth in the Internet, and in particular of the WorldWide Web (WWW), which is one of the facilities provided via the Internet. The WWW comprises many pages or files of information, distributed across many different servers. Each page is identified by an individual address or xe2x80x9cUniform Resource Locator (URL)xe2x80x9d. Each URL denotes both a server machine, and a particular file or page on that machine. There may be many pages or URLs resident on a single server.
Typically, to utilise the WWW, a user runs a computer program called a Web browser on a client computer system such as a personal computer. Examples of widely available Web browsers include the xe2x80x9cWebExplorerxe2x80x9d Web browser provided by International Business Machines Corporation in the OS/2(copyright) Operating System software, or the xe2x80x9cNavigatorxe2x80x9d Web browser available from Netscape Communications Corporation. (xe2x80x9cOS/2xe2x80x9d is a registered trademark of International Business Machines Corporation.) The user interacts with the Web browser to select a particular URL. The interaction causes the browser to send a request for the page or file identified in the selected URL to the server identified in the selected URL. Typically, the server responds to the request by retrieving the requested page, and transmitting the data for that page back to the requesting client. The client-server interaction is usually performed in accordance with a protocol called the Hypertext Transfer Protocol (xe2x80x9cHTTPxe2x80x9d). The page received by the client is then displayed to the user on a display screen of the client. The client may also cause the server to launch an application, for example to search for WWW pages relating to particular topics.
WWW pages are typically formatted in accordance with a computer programming language known as Hypertext Mark-up Language (xe2x80x9cHTMLxe2x80x9d). Thus a typical WWW page includes text together with embedded formatting commands, referred to as tags, that can be employed to control for example font style, font size, lay-out etc. The Web browser parses the HTML script in order to display the text in accordance with the specified format. In addition, an HTML page also contain a reference, in terms of another URL, to a portion of multimedia data such as an image, video segment, or audio file. The Web Browser responds to such a reference by retrieving and displaying or playing the multimedia data. Alternatively, the multimedia data may reside on its own WWW page, without surrounding HTML text.
Most WWW pages also contain one or more references to other WWW pages, which need not reside on the same server as the original page. Such references may be activated by the user selecting particular locations on the screen, typically by clicking a mouse control button. These references or locations are known as hyperlinks, and are typically flagged by the Web browser in a particular manner. For example, any text associated with a hyperlink may be displayed in a different colour. If a user selects the hyperlinked text, then the referenced page is retrieved and replaces the currently displayed page.
Further information about HTML and the WWW can be found in xe2x80x9cWorld Wide Web and HTMLxe2x80x9d by Douglas McArthur, p18-26 in Dr Dobbs Journal, December 1994, and in xe2x80x9cThe HTML SourceBookxe2x80x9d by Ian Graham, John Wiley, N.Y., 1995.
In accordance with the present invention, there is now provided a data communications network comprising: a plurality of geographically spaced wireless transmitters each for transmitting a different network address, and, at least one mobile user terminal having a wireless receiver for receiving the network addresses transmitted by the transmitters, a wireless transmitter for transmitting requests for delivery of data files from remote locations identified by the network addresses, a wireless receiver for receiving from the remote location the data files identified by the network addresses, and output means for outputting the data files received to a user.
Preferably, the network addresses each comprise a Uniform Resource Locator and the data files each comprise a World Wide Web page.
In preferred embodiments of the present invention, the network comprises a plurality of geographically spaced base stations each comprising a receiver for receiving the requests for delivery transmitted by each remote user terminal and for forwarding the requests for delivery to the remote locations identified by the network addresses via the Internet.
In use, each transmitter may continuously transmit the network address. Alteratively, in use, each transmitter may transmit the network address on detection of an interrogation signal generated by each user terminal.
The output means may comprise a display device for displaying the data files received. Furthermore, the output means may comprise an audio output device for generating an audio output as a function of the data files received.
Viewing the present invention from another aspect there is now provided a method of accessing a data file in a data communications network, the method comprising: transmitting, by wireless communications, a different network address from each of a plurality of geographically spaced wireless transmitters; receiving, in a mobile user terminal, by wireless communications, the network addresses transmitted by the transmitters; transmitting from the mobile user terminal, by wireless communications, requests for delivery of data files from remote locations identified by the network addresses; receiving, by wireless communications, in the user terminal, the data files identified by the network addresses from the remote locations; and, outputting, by the user terminal, the data files received.